The present study has been undertaken to assess the effect of different processing methods on the antinutritional factors viz. oxalic acid, phytate phosphorous and tannin content and antimicrobial activity of Cassia tara seeds in order to assess the feasibility of utilizing the weed seeds as a rich food source of protein. The results indicted that oxalic acid content was significantly reduced in all processing methods viz., 18 hrs soaked, 24 hrs soaked, germinated, roasted, pressure cooked, and microwave cooked. Except in 12 hrs soaked and boiled seeds, significant reduction was observed in tannin content in all the processing methods studied. The content of phytate phosphorous was also significantly reduced except in seeds soaked for 12 hrs and 18 hrs. Anti bacterial activity was not observed in Cassia tara raw seed extract or in extracts from different processing methods at the concentrations of 5%, 7.5%, and 10% against Staphylococcus aureus, Proteus vulgaris and Escherichia coli.